Ulrik Beierholm has contributed to a paper titled 'Dopamine Modulates Reward-Related Vigor', published in Neuropsychopharmacology on 18th February 2013.

Paper summary

Making the right choices in life is not enough to guarantee success, another factor is how much vigour and energy one applies to problems. How this relates to the explicit and implicit rewards obtainable in the environment is a very relevant question. E.g. how hard are you willing to work for your current salary?

Inspired by studies of movement vigour in rats we have tested a mathematical model of how humans should change their movement speeds (i.e. vigour) as the rewards in their environment change. Not only do humans movements seem to be highly influenced by the changing rewards but this influence seems to be carried by the neuro-modulator Dopamine. Giving human subjects the drug levodopa (which increases dopamine in the nervous system) caused a larger influence by the rewards on the movement speeds.

This potentially has a number of implications for how the nervous system encodes rewards and movement vigour, as well as for dopamine related diseases such as Parkinsons.